Cork Warts on Leaves of Gnetum L. (Gnetaceae) and its Phylloplane Fungi

The cork warts on leaves of plants appear to be a response to mechanical injuries or pathogen penetrations. Many of Gnetum species regularly form cork warts on leaf surfaces and stems. The authors have searched anatomy, morphology and development of cork warts and also estimated evaluation of probable influence to its origin by phylloplane fungi. Leaves of two species of Gnetaceae family G. gnemon and G. montanum have been investigated for anatomical and morphological studies of cork warts and for mycological research. Herbarial specimens of 13 Gnetum species have been searched. They have successfully extracted 15 species of phylloplane ascomycetes that appear to influence negatively on continuity of leaf epidermis and being able to existing as parasites as well. The most frequent species were Cladosporium cladosporioides, which became a dominant indicating 100% of frequency index and representatives of Fusarium and Phoma genera. The frequency index of latter numbered 36% and 20%, correspondingly. Five species of Penicillium ascomycetes were also determined as frequent.